"For the record this Guitar Hero s--t is breach of contract on a Bullys part and there will be a proper addressing of this and retraction," Courtney wrote on her Twitter page. "WE are going to sue the s--t out of ACtivision we being the Trust the Estate the LLC the various LLCs Cobain Enterprises."

And Cobain's Nirvana bandmates, Dave Grohl and Krist Novolesic, who confirmed they have no say in the use of the late musician's likeness, released a joint statement on Thursday criticizing the game.

"We want people to know that we are dismayed and very disappointed in the way a facsimile of Kurt is used in the Guitar Hero game. The name and likeness of Kurt Cobain are the sole property of his estate — we have no control whatsoever in that area," they said in a statement released to Access Hollywood. "While we were aware of Kurt's image being used with two Nirvana songs, we didn't know players have the ability to unlock the character. This feature allows the character to be used with any kind of song the player wants. We urge Activision to do the right thing in 're-locking' Kurt's character so that this won't continue in the future.

"It's hard to watch an image of Kurt pantomiming other artists' music alongside cartoon characters," their statement continued. "Kurt Cobain wrote songs that hold a lot of meaning to people all over the world. We feel he deserves better."

However, following these criticisms, the company defended itself in a statement to Access.

"Guitar Hero secured the necessary licensing rights from the Cobain estate in a written agreement signed by Courtney Love to use Kurt Cobain's likeness as a fully playable character in Guitar Hero® 5," the company said in the statement, to which Courtney responded on her Twitter page.

"Activision has made thier press release, we shall make ours and we shall seek acyive damages against these f***ers," she Tweeted.